FREMM wasn't an alternative to Type 45. T45 was what we developed after abandoning the joint project from which the French & Italians got Horizon. We kept PAAMS from that project, though with SAMPSON instead of EMPAR.I, for one am very glad we didn't participate in FREMM as we ultimately came out with a more capable (vastly more capable compared to T42 and cheaper to run) ship than we would have done with FREMM. There is a reason why T45 is a more expensive ship (excluding poor management decisions) after all.
By the time FREMM started, Type 45 & Horizon were already well under way, with three T45s building when the first FREMM development & production contract was awarded. Our participation would have been in place of developing Type 26.